Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chines...Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chinese pine （Pinus tabuliformis Carr.） clonal seed orchard. Treatments （0, 250, 500, or 1000 mg L -1 ） were applied during three periods （June- July, July-August and August-September） in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 （500 mg L -1 ） from June to September had significantly more female strobili and immature cones than controls and other treatments （p≤0.0001）. The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls （p≤0.0001）, while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments （p≤0.0001）. Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls （p0.05）, but it had no effect on immature cone production （p0.05）. These results are important for improving seed production and seed orchard management of Chinese pine.展开更多
Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and...Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and how additional CCT family genes regulate heading date in rice, we classified these genes into five groups based on their diurnal expression patterns. The expression patterns of genes in the same subfamily or in close phylogenetic clades tended to be similar. We generated knockout mutants of the entire gene family via CRISPR/Cas9. The heading dates of knockout mutants of only 4 of 14 genes previously shown to regulate heading date were altered, pointing to functional redundancy of CCT family genes in regulating this trait. Analysis of mutants of four other genes showed that OsCCT22, OsCCT38, and OsCCT41 suppress heading under long-day conditions and promote heading under short-day conditions. OsCCT03 promotes heading under both conditions and upregulates the expression of Hd1 and Ehd1, a phenomenon not previously reported for other such genes. To date, at least 18 CCT domaincontaining genes involved in regulating heading have been identified, providing diverse, flexible gene combinations for generating rice varieties with a given heading date.展开更多
基金Partial funding for this research was provided by The State Forestry Administration of China(No.2006-85)
文摘Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chinese pine （Pinus tabuliformis Carr.） clonal seed orchard. Treatments （0, 250, 500, or 1000 mg L -1 ） were applied during three periods （June- July, July-August and August-September） in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 （500 mg L -1 ） from June to September had significantly more female strobili and immature cones than controls and other treatments （p≤0.0001）. The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls （p≤0.0001）, while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments （p≤0.0001）. Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls （p0.05）, but it had no effect on immature cone production （p0.05）. These results are important for improving seed production and seed orchard management of Chinese pine.
基金This study was supported by the National Special Program for Research of Transgenic Plants of China(2011ZX08009-001-002)the National Natural Science Foundation of China(31701054)the Natural Science Foundation of Jiangxi Province(20192BAB214013)。
文摘Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and how additional CCT family genes regulate heading date in rice, we classified these genes into five groups based on their diurnal expression patterns. The expression patterns of genes in the same subfamily or in close phylogenetic clades tended to be similar. We generated knockout mutants of the entire gene family via CRISPR/Cas9. The heading dates of knockout mutants of only 4 of 14 genes previously shown to regulate heading date were altered, pointing to functional redundancy of CCT family genes in regulating this trait. Analysis of mutants of four other genes showed that OsCCT22, OsCCT38, and OsCCT41 suppress heading under long-day conditions and promote heading under short-day conditions. OsCCT03 promotes heading under both conditions and upregulates the expression of Hd1 and Ehd1, a phenomenon not previously reported for other such genes. To date, at least 18 CCT domaincontaining genes involved in regulating heading have been identified, providing diverse, flexible gene combinations for generating rice varieties with a given heading date.
